The invention herein described relates generally to a self-contained electric motor driven pump unit and, more particularly, to such a pump unit that is particularly suited for use in diesel fuel delivery systems for engines.
Various attempts have been made to integrate a pump, electric motor and electronic motor controller into a single compact package. Reference may be had to U.S. Pat. Nos. 4,955,790, 4,998,865, 5,053,664, 5,092,748 and 5,120,201, for examples. These prior attempts have associated therewith one or more drawbacks, including high cost, difficult assembly, poor performance and others. Thus, a continuing need remains for a commercially viable integrated pump-motor-controller unit that overcomes one or more these drawbacks.
The present invention satisfies the aforesaid need by providing an integrated pump unit having the below summarized and hereinafter described features.
According to one aspect of the invention, an integrated pump unit comprises a housing; a pump contained within the housing and including a rotating pump element; and a motor contained within the housing, the motor including a stator having stator coils fixed in relation to the housing and a motor rotor surrounding the stator coils and supported for rotation in the housing.
In a preferred embodiment, a drive coupling is provided for drivingly coupling the motor rotor to the rotating pump element. The drive coupling is radially supported independently of the motor rotor and the rotating pump element, and the pump unit may further comprise an axially extending central support member on which the drive coupling is rotatably supported. The stator may also be radially supported on the central support member.
The pump may be a rotary vane pump including a vane pump rotor supported on the drive coupling which in turn is supported on the central support member for rotation. Preferably the drive coupling is axially shiftable relative to the motor rotor and the rotating pump element.
A preferred drive coupling has a radially enlarged end portion for coupling to the motor rotor and a radially reduced end portion for rotatably coupling to the rotating pump element. The radially enlarged end portion of the drive coupling and the rotor have axially extending ribs and slots for rotatably coupling the drive coupling to the rotor. The rotating pump member may be rotatably supported on the radially reduced end portion of the drive coupling; and the radially enlarged and reduced end portions of the drive coupling may be joined by a plurality of radially extending spokes defining flow passages therebetween.
A preferred pump includes porting members on opposite sides of the rotating pump member for supplying and discharging fluid to and from the rotating pump member, and one of the porting members includes a central passage through which the radially reduced end portion of the drive coupling extends. The pump may include an eccentric ring sandwiched between the porting members and having an eccentric interior chamber, and the rotating pump member may include a vane pump rotor disposed in the eccentric interior chamber. The porting members, vane pump rotor and eccentric ring preferably are contained with the housing for limited axial shifting movement.
A preferred motor rotor includes a radially outer back-iron and a rotor magnet secured to the back-iron. The rotor magnet is made from a plastic bonded magnet material that is insert molded into the rotor back-iron. The motor rotor rotatably supported at its outer diameter by a journal surface on an inner diameter surface of the housing.
A sensor printed circuit board, which may be positioned adjacent an end of the rotor, includes at least one sensor for sensing passage of the magnetic poles of the motor rotor. The sensor or sensors preferably are Hall-effect sensors.
A motor controller may be contained with the housing, and more specifically in an electronics housing member. The controller preferably includes a printed circuit board contained with the electronics housing member. The electronics housing member has a pair of axially extending opposed channels, and the printed circuit board is axially inserted into and between the opposed channels.
According to another aspect of the invention, an integrated pump unit comprises a housing; a pump contained within the housing and including a rotating pump element; a motor contained within the housing, the motor including a stator having stator coils fixed in relation to the housing and a motor rotor surrounding the stator coils and supported for rotation in the housing; and an axially extending central support member mounted in the housing, the central support radially supporting the stator and pump rotor. In a preferred embodiment, the pump includes porting members on opposite sides of the rotating pump member for supplying and discharging fluid to and from the rotating pump member, and one of the porting members supports one end of the central support member. An anti-rotation connection preferably is provided between the one porting member and the central support member; and the porting members and pump member preferably are contained with the housing for limited axial shifting movement relative to the central support member.
According to a further aspect of the invention, an integrated pump unit comprises a housing; a pump contained within the housing and including a rotating pump element; a motor contained within the housing; and an axially extending central support member mounted in the housing against rotation, the central support and pump including telescoping anti-rotation elements cooperating to prevent rotation of the pump relative to the housing. In a preferred embodiment, the telescoping anti-rotation elements include axially extending tabs and slots.
According to yet another aspect of the invention, an integrated pump unit comprises a housing including an interior wall separating wet and dry portions of the housing; a pump contained within the wet housing portion and including a rotating pump element; a motor contained within the wet housing portion and drivingly connected to the pump; and a controller contained within the dry housing portion, and wherein the interior wall is made of a molded polymer material and has molded therein electrical pass-throughs via which the controller is connected to the motor.
According to still another aspect of the invention, an integrated pump unit comprises a housing including an interior wall separating wet and dry portions of the housing disposed along a longitudinal axis of the housing; a pump contained within the wet housing portion and including a rotating pump element; a motor contained within the wet housing portion and drivingly connected to the pump; and a controller contained within the dry housing portion, the controller including a printed circuit board axially inserted in the housing and axially mated with an electrical connector.
According to another aspect of the invention, an integrated pump unit comprises a housing including an interior wall separating wet and dry portions of the housing disposed along a longitudinal axis of the housing; a pump contained within the wet housing portion and including a rotating pump element disposed between inlet and outlet port members; a motor contained within the wet housing portion and including a motor rotor drivingly connected to the pump, the motor rotor being axially retained in a region bounded by the outlet port member and the interior wall; and a controller contained within the dry housing portion.
According to a still further aspect of the invention, an integrated pump unit comprises a housing including an interior wall separating wet and dry portions of the housing disposed along a longitudinal axis of the housing; a pump contained within the wet housing portion and including a rotating pump element disposed between inlet and outlet port members; a motor contained within the wet housing portion and including a motor rotor drivingly connected to the pump; a controller contained within the dry housing portion; and a printed circuit board contained within the wet housing portion and including at least one sensor for detecting a position of the motor rotor and providing such position to the controller.
Another aspect of invention provides an integrated pump unit comprising a housing; a motor contained within the housing; and a vane pump contained within the housing and driven by the motor, the pump including a pump rotor having a rotation axis and a plurality of circumferentially spaced apart grooves opening to an outer periphery of the rotor; an eccentric ring having a wall bounding a pump chamber that is eccentric to the rotation axis of the pump rotor; a vane contained within each groove of the pump rotor and cooperating with the pump chamber wall and pump rotor to form pockets that expand and contract in volume during rotation of the pump rotor within the pump chamber; and porting members on opposite sides of the pump rotor for supplying and discharging fluid to and from the pockets, at least one of the porting members including a pair of radially spaced apart arcuate ports for respectively communicating with radially inner and outer regions of the pocket.
A still another aspect of the invention provides an integrated pump unit comprising a housing having a longitudinal axis; a pump in the housing and including a rotating pump element disposed between inlet and outlet port members; a motor contained within the housing and including a motor rotor; and a drive coupling connecting the motor rotor to the rotating pump element, the drive coupling, rotating pump element and motor rotor including axially telescoping anti-rotation elements cooperating to connect the rotating pump element, drive coupling and motor rotor for common rotation while enabling axial assembly of the rotating pump element, drive coupling and motor rotor into the housing from one end of the housing.
According to a further aspect of the invention, an integrated pump unit comprises a housing; a pump in the housing; a motor contained within the housing for driving the pump; and a controller contained with the housing, the controller including Mosfet drivers and using synchronous rectification to minimize dissipation in the Mosfet drivers.
Further aspects of the invention relate to materials, fabrication and assembly of the various pump unit components as herein described.
To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.